1. Ecosystems and communities

2. Weather and Climate Weather Climate
Day-to-Day variations in conditions
Climate
Year-after-Year patterns of temperature and precipitation
Factors that affect CLIMATE?

3. The Greenhouse Effect Greenhouse Gases Why is this important?
Carbon Dioxide, Methane, Water Vapor, CFCs
Why is this important?

4. Where do Organisms Live?
Tolerance: the range of conditions under which an organism can survive and reproduce.
Habitat: the general place where an organism lives
Niche: An organism’s role in an ecosystem, including how it interacts with biotic and abiotic factors, plus the resources it uses

5. Competition in Ecosystems
Definition: When organisms attempt to use the same resource
Intraspecific – between members of the same species
Interspecific – between members of different species
Competitive Exclusion Principle
No two species can occupy exactly the same niche at the same time
If two species attempt to occupy the same niche at the same time, one will lose out

6. Predation and Herbivory
Predation: One animal (predator) captures and feed on another animal (prey)
Herbivory: One animal (herbivore) feeds on primary producers (i.e. plants)
*BOTH affect the population size and distribution of what is eaten
What is going on here??

7. Keystone Species
Definition: A species that can cause dramatic changes in ecosystem and/or community structure

8. Symbiosis
Definition: Relationship in which 2 organisms live closely together
Types: Mutualism, Parasitism, Commensalism
Mutualism: Both organisms benefit
Parasitism: One organism benefits and the other is harmed
Commensalism: One organism benefits and the other is unaffected

9. Is it Mutualism, Parasitism, or Commensalism?
Clownfish and Sea Anemone
Tick and Human
Caterpillar and Wasp (larvae)
Ants and Acacia
Whale and Barnacles

10. Ecological Succession
Definition: A series of predictable changes that occur in a community over time
Ecosystems change over time ESPECIALLY after disturbances
How do they change?
Species die out
New species move in
# of total species increases over time (generally)

11. Primary Succession
Occurs on a surface where no ecosystem existed before.
Pioneer Species
Climax Community

12. What types of disturbances lead to primary succession?
Pioneer species: Lichen
After a volcanic eruption
Following a retreating glacier

13. Secondary Succession
Occurs on a surface where an ecosystem has previously existed.
Proceeds faster – why??

14. Climax Communities
Definition: a stable, mature community at the final stage of succession
After natural disturbances, original climax community is often reproduced
After human-caused disturbances, ecosystems may OR may not return to original climax